Deep vein thrombosis (DVT) is a common medical condition that may be potentially fatal by becoming a source or lead to pulmonary emboli (PE). DVT is especially common in patients who are immobilized for relatively long periods of time due to a medical or surgical illness, or patients with multiple trauma, or patients with malignant diseases, or patients who are paraplegic and quadriplegic, pregnant, and/or having other medical conditions. It can also develop in otherwise healthy individuals, after prolonged sitting and immobilization. Current treatments may comprise anticoagulation, which may carry significant inherent risks, surgical approaches (for prevention of PE after DVT has developed) of various filter installations, which are not completely effective, and the attempted prevention of DVT by mechanical devices such as graduated leg stockings, external pneumatic calf compression, and pharmacological agents such as low does of Heparin or Coumadin.
The main cause of DVT is venous stasis, i.e., the lack of effective venous blood flow from the calves due to extended periods of immobilization. A very effective means for preventing DVT is muscle contraction of the calves which pumps centrally venous blood, thus preventing stasis in the proximal veins, e.g., pelvis as well. If a patient can continuously move his or her legs or exercise, e.g., "a stepping on brakes" movement against a leg board, many cases of DVT can be prevented. However, most of the patients that develop DVT are not in a condition to so exercise voluntarily.
Such lack of efficient or effective venous flow from the legs can result in other problems which, while they may not be life threatening, are associated with significant discomfort and are aesthetically unappealing, e.g., idiopathic ankle edema and edema associated with venostasis and varicose veins. Effective muscle pumping can significantly reduce the morbidity associated with these conditions also.